1. Field of the Invention
The present invention relates generally to magnetic tape recording apparatus and more particularly to storage bins for storing an endless loop of magnetic recording tape which is folded back and forth in serpentine configuration.
2. Description of the Prior Art
In high speed magnetic tape duplicating and recording systems as well as in data processing equipment utilizing magnetic tape, it is now common practice to utilize loop storage bins in which a long length of tape is folded back and forth in serpentine fashion in a generally rectangular shaped storage bin having front and back walls which are separated only slightly more than the width of the tape to be stored. In such apparatus, the tape is normally loaded from the top and caused to loop back and forth upon itself as the other end is withdrawn from the bottom of the loop pile. The tape's own weight is used to compact the serpentine loops within the bin. Prior art U.S. Pat. Nos., which may be of interest by way of general background, are Gibson 2,542,506, MacDonald 2,889,491, Fritzinger 2,908,767 and Boyden 3,201,525.
One of the problems associated with prior art loop bin constructions has been overcoming the friction between the bottom surface of the bin and the portions of the tape being withdrawn from the bottom of the loop pack. One prior art attempt to overcome this problem has been to use a plurality of closely spaced rollers to form the bottom and partial side portions of the bin. Another solution has been to utilize a plurality of short, belt conveyers such as is shown in the U.S. Pat. No. 4,000,516 of Kazuo Watanabe et al. However, such solutions are mechanically complex and quite expensive in that the rollers are conveyers must be provided with expensive low friction bearings and smoothly polished surfaces.
Another prior art problem is associated with the perturbations in speed of the portion of the tape being withdrawn from the bottom of the stack due to differing frictional forces on various portions of the folded loops at the bottom of the bin. The primary prior art solution to the problem has been to utilize a heavy flywheel controlled damping roller in the tape transport mechanism. Although such means are successful in reducing tape speed fluctuations at the recording or playback head with a measure of success, there is definitely room for improvement.
Still another problem with prior art storage bin designs relates to the ability of the device to store a large quantity of folded tape within a particular bin volume. It has been found that the amount of tape which can be stored in a particular bin volume is directly related to the manner in which the tape is folded within the bin, i.e., it appears that the more folds there are, the larger the quantity of tape that can be stored within a given volume and the more mobile the tape is at the bottom of the stack.